Observational study of persons with HIV infection and a documented history of a CD4 count of 50 or less in the precious 2 years, who have evidence by blood test of CMV exposure but do not yet have CMV disease. Thses people will be recruited by flyers and advertisements to the CARE Clinic for a screening visit to be consented, have a brief history and physical, and a blood test of 2 tablespoons (30cc), and a dilated eye exam by a opthalmologist.